Old plugins install with their own installer somewhere.
Old plugins find that somewhere as before.
OpenCPN loads the old plugins like before
Old plugins are uninstalled just as before.
PI Installer can install new plugins and puts them elsewhere
PI Installer's new plugins use GetPluginDataDir and must not care where elsewhere is.
PI Installer's use tarballs and metadata.xml for installation.
PI Installer after selection of “+”
PI Installer downloading after selection of “Upload” or “Reinstall”
PI Installer download completed and plugin installed
PI Installer incompatible notice
PI Installer selection of Catalogs